512  CONTEIBUTIONS    TO    ECONOMIC    GEOLOGY,  1904.         [bull.  260. 
Descriptions  of  localities. — During  1904  the  Selma  chalk  was  care- 
fully mapped  throughout  the  Tombigbee  River  basin  in  Mississippi, 
particular  attention  being  paid  to  the  district  between  the  Alabama 
line  and  Columbus,  because  the  transportation  facilities  in  this  area 
are  more  favorable  to  the  erection  of  a  cement  plant  than  farther 
north  in  the  State. 
In  the  following  pages  descriptions  will  be  given  of  the  various 
localities  visited  during  this  work.  Samples  were  taken  from  all  of 
these  localities,  and  many  of  these  samples  have  been  analyzed,  the 
results  being  given  below.  The  descriptions  are  given  in  order, 
going  up  the  Tombigbee  River  from  the  Alabama-Mississippi  line. 
At  the  big  elbow  bend  in  Oaknoxubee  Iviver,  one-fourth  mile  below 
the  wagon- bridge  at  Macon,  the  river  has  formed  a  bluff  75  feet  high 
on  the  south  side  of  the  stream.  The  entire  cliff  is  formed  of  the 
Selma  chalk.  It  is  a  solid  mass  of  white  chalk,  nonfossiliferous 
and  apparently  without  bedding  planes,  but  if  the  bluff  is  viewed  at 
a  distance  the  stratification  of  the  material  is  shoAvn  by  the  unequal 
hardness  of  the  strata,  causing  some  to  weather  more  rapidly  than 
others.  There  is  a  marked  dip  to  the  south.  All  the  smaller  streams 
flowing  into  the  Oaknoxubee  have  channeled  their  beds  into  the  pure 
white  limestone.  A  sample  was  collected  from  the  bluff  on  the 
( )aknoxubee. 
The  following  analysis  of  this  sample  was  made  by  H.  C.  McNeil 
in  the  laboratory  of  the  United  States  Geological  Survey: 
Analysis  of  Ovinia   limestone,   near  Macon,  Miss. 
Silica  (SiO,) 9.09 
Alumina  ( A1._,03) 
Iron  oxide  (Fe,(J3)  .  |    ..47 
Lime  carbonate  (CaC03) -  -  - 80. 99 
Magnesium  carbonate  ( MgC03) 0. 00 
Water  1.08 
About  1-J-  miles  northeast  of  the  town  of  Dekalb,  near  the  east 
edge  of  the  area  of  the  Lagrange  formation  on  Sucarnooche  Creek, 
is  a  bed  of  lignite  3  feet  thick,  which  outcrops  a  few  feet  above  the 
bed  of  the  creek.  This  bed  has  been  opened  up  with  a  view  of  devel- 
oping the  vein.  A  level  was  run  into  the  hill  "JO  feet  and  con- 
siderable lignite  taken  out.  It  was  found  to  be  of  excellent  quality, 
and  was  burned  in  the  office  of  the  chancery  clerk,  Mr.  Samuel  O. 
Bell,  at  Dekalb.  The  following  analyses  were  made,  No.  1  by  J.  C. 
Long  and  No,  2  by  li.  T.  Pittman ; 
